src/glu/sgi/libnurbs/internals/jarcloc.h

   1 /*
   2 ** License Applicability. Except to the extent portions of this file are
   3 ** made subject to an alternative license as permitted in the SGI Free
   4 ** Software License B, Version 1.1 (the "License"), the contents of this
   5 ** file are subject only to the provisions of the License. You may not use
   6 ** this file except in compliance with the License. You may obtain a copy
   7 ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
   8 ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
   9 **
  10 ** http://oss.sgi.com/projects/FreeB
  11 **
  12 ** Note that, as provided in the License, the Software is distributed on an
  13 ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
  14 ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
  15 ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
  16 ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
  17 **
  18 ** Original Code. The Original Code is: OpenGL Sample Implementation,
  19 ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
  20 ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
  21 ** Copyright in any portions created by third parties is as indicated
  22 ** elsewhere herein. All Rights Reserved.
  23 **
  24 ** Additional Notice Provisions: The application programming interfaces
  25 ** established by SGI in conjunction with the Original Code are The
  26 ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
  27 ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
  28 ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
  29 ** Window System(R) (Version 1.3), released October 19, 1998. This software
  30 ** was created using the OpenGL(R) version 1.2.1 Sample Implementation
  31 ** published by SGI, but has not been independently verified as being
  32 ** compliant with the OpenGL(R) version 1.2.1 Specification.
  33 */
  34
  35 /*
  36  * jarcloc.h
  37  *
  38  */
  39
  40 #ifndef __glujarcloc_h_
  41 #define __glujarcloc_h_
  42
  43 #include "arc.h"
  44
  45 class Jarcloc {
  46 private:
  47     Arc_ptr             arc;
  48     TrimVertex          *p;
  49     TrimVertex          *plast;
  50 public:
  51     inline void         init( Arc_ptr a, long first, long last ) { arc = a; p=&a->pwlArc->pts[first]; plast = &a->pwlArc->pts[last]; }
  52     inline TrimVertex * getnextpt( void );
  53     inline TrimVertex * getprevpt( void );
  54     inline void         reverse();
  55 };
  56
  57 inline void
  58 Jarcloc::reverse()
  59 {
  60     if( plast == &arc->pwlArc->pts[0] )
  61         plast =  &arc->pwlArc->pts[arc->pwlArc->npts - 1];
  62     else
  63         plast =  &arc->pwlArc->pts[0];
  64 }
  65
  66 inline TrimVertex *
  67 Jarcloc::getnextpt()
  68 {
  69     assert( p <= plast );
  70     if( p == plast ) {
  71         arc = arc->next;
  72         p = &arc->pwlArc->pts[0];
  73         plast = &arc->pwlArc->pts[arc->pwlArc->npts - 1];
  74         assert( p < plast );
  75     }
  76     return p++;
  77 }
  78
  79 inline TrimVertex *
  80 Jarcloc::getprevpt()
  81 {
  82     assert( p >= plast );
  83     if( p == plast ) {
  84         arc = arc->prev;
  85         p = &arc->pwlArc->pts[arc->pwlArc->npts - 1];
  86         plast = &arc->pwlArc->pts[0];
  87         assert( p > plast );
  88     }
  89     return p--;
  90 }
  91 #endif /* __glujarcloc_h_ */